The field of the invention is transmission line insulators although the conductive clip of this invention is a conductor rather than an insulator. Transmission and distribution line insulators are typically made from a series of ceramic bells which are joined together by a metallic eye cemented into one bell which is pinned to an insulator cap having two clevis ears which is attached to the adjacent bell. These metal members are typically cast or forged maleable iron having a heavy galvanized coating to reduce corrosion.
Upon weathering these metal members tend to corrode and form an insulative coating such as a layer of zinc sulfide. Such coatings tend to inhibit electrical conduction from the clevis ears or pin to the eye of an adjacent insulative member. While the ceramic bells are intended to prevent the flow of electricity, a certain amount of leakage current is associated with the insulators and this leakage current is sufficient to create a sparking or arcing across the sulfide or other corrosive surface of adjacent metallic members.
This corrosive and insulative coating is generally worn away when there is a pull of greater than 100 pounds along the insulators. Where there is less than 100 pounds, particularly when there is less than 50 pounds of tension, there is not sufficient force to wear away the corrosive coatings and the above described arcing or sparking creates television and radio interference. Thus, slack span dead ends or wherever small conductor sizes are terminated gives rise to the undesirable interference.
Historically these radio or television interference problems arising from lightly loaded transmission or distribution line insulators have been attacked by the use of bonding brushes. These brushes were formed from hard metal bristles which were intended to cut into the sulfide coating which had formed on the metal parts. The bonding brushes, however, were not only expensive but also themselves tended to corrode and after a short time radio interference increased to a level greater than that occurring with no brushes at all.
Another approach was to use a simple wire bonding clip such as that disclosed in U.S. Pat. No. 3,270,124. While this device was inexpensive, it was found that the clips did not make sufficient electrical contact and that noise would build up within a year after the installation of the clip. Furthermore, the contact points of the clip often worked their way into an opening between the pin and the eye through which the pin was inserted.
Yet another approach was to connect a conductor between adjacent metal members. This approach was not only expensive but often required live line work together with the necessity of intimate contact with the metal members.